Delivery-date: Mon, 24 Mar 2025 15:00:58 -0700 Received: from mail-qv1-f58.google.com ([209.85.219.58]) by mail.fairlystable.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.94.2) (envelope-from ) id 1twpqr-0002LL-O4 for bitcoindev@gnusha.org; Mon, 24 Mar 2025 15:00:58 -0700 Received: by mail-qv1-f58.google.com with SMTP id 6a1803df08f44-6e900f6dcadsf106354896d6.3 for ; Mon, 24 Mar 2025 15:00:57 -0700 (PDT) ARC-Seal: i=2; a=rsa-sha256; t=1742853652; cv=pass; d=google.com; s=arc-20240605; b=WHBow7QNdp9NxgvGvDFplqc9MMHI6SeDp+z6P+FQ976M2aUdiXztOj39FIl85Qt3X4 QOmggDH4hZoxNFjab8HTIK25O/crqm/D8ojQw9nP1xHjiAUrBTRIcEYkpGbBfRLzgivF TorUV9bwfBfdxGZkkt3wx+U84cI/LQIHH9MzrvL8IBOLwSXOH6kQboOnTFX1Cm+46AlM tU203a26ig6i8uLQCmMEh4qjcZSy6+blcEHPRsvjI7D9W7jRDpl1dAcCCTellqLvQnSB GK97IdXniWKHQ07UKQNlxJQbHtyPJo7al2M+/gQyrBW++o7DkaHO1TrgbXb64GywlPJB N/Og== ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20240605; h=list-unsubscribe:list-subscribe:list-archive:list-help:list-post :list-id:mailing-list:precedence:in-reply-to:content-disposition :mime-version:references:message-id:subject:cc:to:from:date :feedback-id:sender:dkim-signature; bh=RSfC7UDDlcgQ/GRojuuZibmKJLMPcSy3V2GaiVfso/Y=; fh=ie0yVaACf5A7ctWkZSHGXKZTBISKyecq1DuJjPS1+TY=; b=Z4pDRQ+2iALCzeGkAv9m4tPLNuZHWBNE+JUy9jkzhqI/BiOnaDlnVko+Kyu8KDupvT jtg8hiQYlOU9C+4IR7fRwoOCf2TD+lbhAjXaF5vG0zhT54KQaveoxBo1UnDHeVFchD7c wVQzrnPR1INNwe/FaNi46LsSqwl1m5yq67b80lZ218H3a1Fo3f5gZViCUKkCwK9PK5xj lg94nbmdB4LERuJ4wNEf7gShLNWjQ3JqAqKLozc6EEN7M+6/yo7cYVtiW44wJk934blg TzO552jREWFtQ6mcX5d1hZaA3Xg70ojHQks0WxVwB+vD3KxUH4uqywSsZRmup9DkAyZ7 cRyQ==; darn=gnusha.org ARC-Authentication-Results: i=2; gmr-mx.google.com; dkim=pass header.i=@messagingengine.com header.s=fm2 header.b=N1H0CVPV; spf=pass (google.com: domain of pete@petertodd.org designates 202.12.124.155 as permitted sender) smtp.mailfrom=pete@petertodd.org DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlegroups.com; s=20230601; t=1742853652; x=1743458452; darn=gnusha.org; h=list-unsubscribe:list-subscribe:list-archive:list-help:list-post :list-id:mailing-list:precedence:x-original-authentication-results :x-original-sender:in-reply-to:content-disposition:mime-version :references:message-id:subject:cc:to:from:date:feedback-id:sender :from:to:cc:subject:date:message-id:reply-to; bh=RSfC7UDDlcgQ/GRojuuZibmKJLMPcSy3V2GaiVfso/Y=; b=Pcts5asVFNvreldeq47e7rzlUWFxcKE23Zkt1eKAiqYVuamnAixXZNRkM4SWqak99J Oc5+IdLXS1SuvCXaqpzM0jE6b3MGhj7S+iOD7C3rgmGASO0oxCAjEieuXCEC8CsCxOF9 OQJ5NvoScf+oKiQ39N3zbVMlN7eZWYsa3HHSNAXerh2F0Ddbxxx7TXL+yik6JF826BTY 8vhMRcTBuiM8F0vDC9LuM95ZoXX/+09sDwv496fdMVF+JLNSiDvCJB7fLUfcS2EogdsN 5Oy3NOPk2m4JltaUqbab+tN692WfvID97uwQcTgKPBTRJ54GYwXrd0fxn4xefx5IdA2A orxQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1742853652; x=1743458452; h=list-unsubscribe:list-subscribe:list-archive:list-help:list-post :list-id:mailing-list:precedence:x-original-authentication-results :x-original-sender:in-reply-to:content-disposition:mime-version :references:message-id:subject:cc:to:from:date:feedback-id :x-beenthere:x-gm-message-state:sender:from:to:cc:subject:date :message-id:reply-to; bh=RSfC7UDDlcgQ/GRojuuZibmKJLMPcSy3V2GaiVfso/Y=; b=eKAx7vJqKAq1Msg2e87XaQahHb3gQaBwnaKv0pYsDV5PjV5cjjru2TkcaspKjKf28h XXFrfGdcSFgEOHAHFCs0GfRuZaL8OuBHyCqAAHZr79tOaFa+IZkBXn2pzddibu2LtmS3 G0J/sICgDZ0wsMXxQEG0dZI9jlLoYuNjvNRKP27/N1WJjpuzcgMByqBRXrpwJCu63UXY R8WXLZLab5Kf3WVW0gK0o2kzC/z7G8lHeOM5P/MXsEofjXXkNlYa88xJ1y9PPJuBiIfG Bb3pzfltcUoVR5dby72O4TVpUnuq5zCH6jYW3W19dPjkRtcSpBTMau1IDhaaeDZf+vIz c0Zw== Sender: bitcoindev@googlegroups.com X-Forwarded-Encrypted: i=2; AJvYcCU6e3qAzVeqW83hJWjRzGbF640RVFxeiGDjPOt3dfYeF1k8yEnOVuVgw+Dxu6Qn5ttolVV/BLXrn/ua@gnusha.org X-Gm-Message-State: AOJu0YzqjrPNei1hR9IxOR9RDuzcIv0iZScIS+OV2jFy0SAuZjWZhVSi s2OXxLWU/xzoTlEsDy4eY/WllR2OBT+HbTFr2235ZU1oKaz46AHp X-Google-Smtp-Source: AGHT+IGanyg/tOi3Y0Zz/PqRKdeB11Z9wTlyrGJEv8yMecgfI0n4PCpRwUKPUk98c8kiLzWckHw3nw== X-Received: by 2002:a05:622a:5a94:b0:476:7f5c:e2fe with SMTP id d75a77b69052e-4771dd53637mr225862851cf.6.1742853651608; Mon, 24 Mar 2025 15:00:51 -0700 (PDT) X-BeenThere: bitcoindev@googlegroups.com; h=ARLLPAKtwUN1lPO4WEglScWoUbxHSKUgRkQQw2DPteiHYJr2Tg== Received: by 2002:a05:622a:8026:b0:476:69c5:ff0b with SMTP id d75a77b69052e-4771c3e376dls43738421cf.1.-pod-prod-09-us; Mon, 24 Mar 2025 15:00:48 -0700 (PDT) X-Received: by 2002:a05:620a:319e:b0:7c5:5585:6c83 with SMTP id af79cd13be357-7c5ba1f81f6mr3019793285a.54.1742853648552; Mon, 24 Mar 2025 15:00:48 -0700 (PDT) Received: by 2002:a05:620a:1271:b0:7c5:3b15:3956 with SMTP id af79cd13be357-7c5b118bdb4ms85a; Mon, 24 Mar 2025 09:17:50 -0700 (PDT) X-Received: by 2002:a05:6122:88d:b0:520:5185:1c31 with SMTP id 71dfb90a1353d-525a850df05mr8680769e0c.9.1742833069915; Mon, 24 Mar 2025 09:17:49 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1742833069; cv=none; d=google.com; s=arc-20240605; b=iT8RPkjv4jZCa7L/+aWhkKIc+fD2N27sIm7BKSY/fOnQumpTrtqDl/JY2V+Cscux6b LVjqtusiYDOQUFPjjoJX6vZn9aAswOwm4TIi9CBFUuSXbeRRj7C8S5CPoIyA5b+SGbH4 QLLPxHmDBuYUaUb2sSES1X4rz0boZ3Lk03v459KTPi4u3ygZeQr0M56Z6TuDHg9Qx88W QesJmO6kMqTbI6/0+C5kyBpMzuMSv5YZxClYQcCpZqNWjsdWlc3atg+mMl8eeVDHznqh yJN3V/pqGP17TPlJqaCrfJuHswQywE8Spub7SciUhvs7JY5eDq7D4eydpyiKr4XX4OFo cGcQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20240605; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:feedback-id:dkim-signature; bh=gGMhAdPpUb9pCS07wa7L6vaz/W9tyttfi/39X1RMlME=; fh=sapDHqhE46zLmMBeB1lkoe0zq8J9+V3Afx71/j8kvug=; b=QxkiYm5N4AcOM5AhSjkrq4geadduqIZMl4Lk0CAD2yfPFPnN5apD66u8iGFj79QM9K wBtQHeUBXnxWUVKCwBhH+BDrnaMv/E8pXAKiBg6LlXOq+COwq8+FGZXSAdROKJcAUUyV eNl14vIs7MfcMNeaqkk6uxfFBzivUjgUvVjnQ3YGlbftl85NEznoJEFuxW7nY903nxRu +8IdiZ2bHM+sscWE65L0DCfxXObp4is8+dLsUdiN+TX3+JaMw5Ahsgsx5qtK+L7Ub8jA LtJguMZHOd4V6RoLf2Vp/u3WV72QsEt0VEPRR2QnwW1RuA6fqEn7KcxPiTd/q+vfNL+W T2Ig==; dara=google.com ARC-Authentication-Results: i=1; gmr-mx.google.com; dkim=pass header.i=@messagingengine.com header.s=fm2 header.b=N1H0CVPV; spf=pass (google.com: domain of pete@petertodd.org designates 202.12.124.155 as permitted sender) smtp.mailfrom=pete@petertodd.org Received: from fhigh-b4-smtp.messagingengine.com (fhigh-b4-smtp.messagingengine.com. [202.12.124.155]) by gmr-mx.google.com with ESMTPS id 71dfb90a1353d-525a74b86d7si365321e0c.3.2025.03.24.09.17.49 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 24 Mar 2025 09:17:49 -0700 (PDT) Received-SPF: pass (google.com: domain of pete@petertodd.org designates 202.12.124.155 as permitted sender) client-ip=202.12.124.155; Received: from phl-compute-10.internal (phl-compute-10.phl.internal [10.202.2.50]) by mailfhigh.stl.internal (Postfix) with ESMTP id 3E6892540109; Mon, 24 Mar 2025 12:17:49 -0400 (EDT) Received: from phl-mailfrontend-01 ([10.202.2.162]) by phl-compute-10.internal (MEProxy); Mon, 24 Mar 2025 12:17:49 -0400 X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeefvddrtddtgdduiedtvdefucetufdoteggodetrf dotffvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdggtfgfnhhsuhgsshgtrhhisggv pdfurfetoffkrfgpnffqhgenuceurghilhhouhhtmecufedttdenucesvcftvggtihhpih gvnhhtshculddquddttddmnecujfgurhepfffhvfevuffkfhggtggujgesghdtreertddt vdenucfhrhhomheprfgvthgvrhcuvfhougguuceophgvthgvsehpvghtvghrthhouggurd horhhgqeenucggtffrrghtthgvrhhnpedttdegtdffteeukeffhfffkeekiefhteduvdet jeeujeffgeevgefhudetjefhveenucffohhmrghinhepghhithhhuhgsrdgtohhmpdhpvg htvghrthhouggurdhorhhgnecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehm rghilhhfrhhomhepphgvthgvsehpvghtvghrthhouggurdhorhhgpdhnsggprhgtphhtth hopedvpdhmohguvgepshhmthhpohhuthdprhgtphhtthhopegrnhhtohhinhgvrdhrihgr rhgusehgmhgrihhlrdgtohhmpdhrtghpthhtohepsghithgtohhinhguvghvsehgohhogh hlvghgrhhouhhpshdrtghomh X-ME-Proxy: Feedback-ID: i525146e8:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Mon, 24 Mar 2025 12:17:48 -0400 (EDT) Received: by localhost (Postfix, from userid 1000) id C7A129FCE8; Mon, 24 Mar 2025 16:17:46 +0000 (UTC) Date: Mon, 24 Mar 2025 16:17:46 +0000 From: Peter Todd To: Antoine Riard Cc: Bitcoin Development Mailing List Subject: Re: [bitcoindev] Re: Standard Unstructured Annex Message-ID: References: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="oK+OhC40TMpcmp+u" Content-Disposition: inline In-Reply-To: X-Original-Sender: pete@petertodd.org X-Original-Authentication-Results: gmr-mx.google.com; dkim=pass header.i=@messagingengine.com header.s=fm2 header.b=N1H0CVPV; spf=pass (google.com: domain of pete@petertodd.org designates 202.12.124.155 as permitted sender) smtp.mailfrom=pete@petertodd.org Precedence: list Mailing-list: list bitcoindev@googlegroups.com; contact bitcoindev+owners@googlegroups.com List-ID: X-Google-Group-Id: 786775582512 List-Post: , List-Help: , List-Archive: , List-Unsubscribe: , X-Spam-Score: -0.8 (/) --oK+OhC40TMpcmp+u Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline On Thu, Mar 20, 2025 at 03:47:16PM -0700, Antoine Riard wrote: > Hi Peter, > > See also that can be relevant for taproot annex support: > https://github.com/bitcoin/bips/pull/1381 Thanks. > > 1) All non-empty annexes start with the byte 0x00, to distinguish them > > from consensus-relevant annexes. This ensures that any use of the > > annex will not conflict with future soft-forks that may assign > > meaning to the annex. > > So IIUC, it would be 1-byte: 0x00 | . Correct. When annex data finally does get a consensus meaning any encoding scheme starting with a non-zero byte will be compatible. Most likely we'll get some tag-length-value encoding scheme. Applications already using annexes who want to also take advantage of new consensus features will of course have to upgrade their encoding schemes to match. But I think that's fine. > > 2) All inputs have an annex. This ensures that use of the annex is > > opt-in, preventing transaction pinning attacks in multi-party > > protocols. This requirement may be relaxed in the future, eg to allow > > spends of keyless outputs, and/or if RBF for witness-only > > replacements is implemented. > > I think it's good to start with all inputs have an annex. It avoids > the kind of issue, like what if the annex size is inflated to downgrade > the feerate of the multi-party transaction (e.g to have a coinjoin > stucking in network mempools). Glad to hear you agree. > One thing that might be missed, without having looked to the code, is > potentially a policy transaction-relay rule to limit the max size of the > annex, to avoid the same concern than above. There shouldn't be max > limit for now, as normally the annex is not standard at all as a taproot > data field. Libre Relay has no limit on OP_Return output size; I'm not going to artificially limit annex usage either. The requirement to opt-in to annex usage should be sufficient. There is a possibility of a multi-party, annex-using, protocol where someone does a pinning attack by re-signing their transaction with a bigger annex. But witness-RBF in combination with replace-by-fee-rate will fix this, so I'm not concerned. No such protocols actually exist yet anyway, so we can figure that out later. -- https://petertodd.org 'peter'[:-1]@petertodd.org -- You received this message because you are subscribed to the Google Groups "Bitcoin Development Mailing List" group. To unsubscribe from this group and stop receiving emails from it, send an email to bitcoindev+unsubscribe@googlegroups.com. To view this discussion visit https://groups.google.com/d/msgid/bitcoindev/Z-GFqu7bfDGdLSa-%40petertodd.org. --oK+OhC40TMpcmp+u Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEE0RcYcKRzsEwFZ3N5Lly11TVRLzcFAmfhhacACgkQLly11TVR LzfO8RAAu9QlkPzFp/M5qDaWouTY8ybXJ7BYdE37ZBRfmP297pwySqWOAT9iwxYU a0C4fW4vm0pLB7UeAF0HumHvVpJepVxqfUMXcYucbgnCKQN5kijAO9A4UQ1HHkMl VDgwTJ8i9V1d8b4xms1aZrEWbi+xIE76DtYQlZObOKnbMLNeEWgNE57vJEo8yM3q 3DWnaPlTK8Zlo11VNI9KiuBF/8ASBWR3eoE25SBgoxbG3BGzAbvjqf1fZqM7wq0Y qssPe92000MZB/JKyrcoMiiyKLGDrQM3MVQwUAZPs/YhMLTZsY77o1lmXw53c5cz Fkdxbf3aOVZGPizuaYT0NDVC4OkZfL7OC2N85JdyMM/XDvqo0aGqD/uGmSLIijyF HiDV+uv/tbITrIaW72aNPodjrUWHdU6XmQCMy5tUaqcY6qSdBT7qm3k9AJcGGe2N SNVtMgepN9yWnFWx/b/Hwt6qrCgXgXMdIN1qiM3pV49iTLIfA+Dt5jOEePctGEPp Qvblz/24fY/JYy1fTzbbyobEx6YNlJqc1qMfOARssQrx4BnHqTExnwR/CHjqD6Az ZsjLzFGAnkewL2Cq2wzwooSV4wWxVzbTtz7oKGsXPCWErUukU37K/CfeUOl5Wj5A kYIgiqGYSEjNSH7APdz9Hm02Ef2kB3I9V+tlfQWTkcPS4nLTpT4= =UvOn -----END PGP SIGNATURE----- --oK+OhC40TMpcmp+u--